1. Field of the Invention
This invention relates to a control apparatus for an engine powering, for example, an automotive vehicle or a ship.
2. Description of the Prior Art
Regarding engines for ships and automotive vehicles, various sensors and switches have recently been used to generate signals representative of engine operating conditions. The signals generated by the sources are inputted into a microcomputer, and are used in a given control program executed by the microcomputer. In general, the control program has routines directed to different controls such as ignition timing control and fuel injection control.
There are different control routines directed to each of the controls. Further, for each of the controls, the type of control routine executed by the microcomputer depends on the form of signals generated by sources (e.g., various sensors and switches).
For example, engines of one type are subjected to spark timing control including knock control using a knock sensor while engines of another type are subjected to spark timing control including change of a spark advance angle, and entirely unrelated to knock control. Thus, the type of control routine for spark timing control executed by the microcomputer depends on the type of engine controlled thereby.
In some cases, various grades (types) of engines are prepared for one model of an automotive vehicle or a ship. In these cases, even for one model of the automotive vehicle or the ship, the control program required must be changed, depending on the grade of engine actually used.
Thus, it is necessary to prepare different types of control apparatuses, including a microcomputer, according to each of the various control routines and signal sources. Specifically, even for one model of an automotive vehicle or a ship having an engine of a grade arbitrarily selected from among different grades, it is necessary to prepare several different types of control apparatuses. Accordingly, there has been a strong demand for the standardization of control apparatuses.